While driving my 230E, about 20 mph, the engine died. I was able to re-start the car and drive about a mile farther when it died again and would not re-start. The fuel pump is not working.
I can make the fuel pump work by jumping pins 7 and 8 on the fuel pump relay connector. So, I guessed that the problem was the relay. I replaced the relay, with a used one, but that didn't fix the problem.
When I turn the ignition key I can hear the relay make a click, but the fuel pump does not start.
Any help would be appreciated.
20 years of operational from a fuel pump ain't bad. My guess is the click indicates the relay is working, sounds like you need a new fuel pump, (they don't last forever). The cost to test the operation of your 20 year old fuel pump is about half the cost of a new fuel pump. Also consider that when a fuel pump fails it takes a tow truck to get home or to the Mercedes shop.
Before replacing the fuel pump I checked the voltage going to it. I can turn the key on and I still don't get any voltage to the pump. The only way I get any voltage to the pump is by jumping number 7 and 8 terminals on the fuel pump relay connector, whether the key is on or not. What all is being bypassed by placing the jumper wire? I don't think the relay is faulty. I have checked every fuse I can find. What else can it be? I apprecaite any help.
I jumped pins 7 and 8 on the relay connector and the fuel pump ran. I was able to start the car with the jumper in place and run it until I turned the key back off. Thanks for your help. Any other ideas?
The number 9 pin on the relay connector has 12 volts when the key is on, as it should. The ground wire (numnber 11) has been tested and it is a good connection. The problem I'm having is that no voltage is reaching the fuel pump when the relay is in place, only when I jump number 7 and 8 pins.
Linear Mode
